treewide: Use struct_size() for kmalloc()-family

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);

This patch makes the changes for kmalloc()-family (and kvmalloc()-family)
uses. It was done via automatic conversion with manual review for the
"CHECKME" non-standard cases noted below, using the following Coccinelle
script:

// pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
//                      sizeof *pkey_cache->table, GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// Same pattern, but can't trivially locate the trailing element name,
// or variable name.
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
expression SOMETHING, COUNT, ELEMENT;
@@

- alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP)
+ alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP)

Signed-off-by: Kees Cook <keescook@chromium.org>

12 files changed, 22 insertions, 29 deletions

diff --git a/drivers/clk/bcm/clk-iproc-asiu.c b/drivers/clk/bcm/clk-iproc-asiu.c
index 4360e481368b..6fb8af506777 100644
--- a/drivers/clk/bcm/clk-iproc-asiu.c
+++ b/drivers/clk/bcm/clk-iproc-asiu.c
@@ -197,8 +197,8 @@ void __init iproc_asiu_setup(struct device_node *node,
 	if (WARN_ON(!asiu))
 		return;
 
-	asiu->clk_data = kzalloc(sizeof(*asiu->clk_data->hws) * num_clks +
-				 sizeof(*asiu->clk_data), GFP_KERNEL);
+	asiu->clk_data = kzalloc(struct_size(asiu->clk_data, hws, num_clks),
+				 GFP_KERNEL);
 	if (WARN_ON(!asiu->clk_data))
 		goto err_clks;
 	asiu->clk_data->num = num_clks;
diff --git a/drivers/clk/bcm/clk-iproc-pll.c b/drivers/clk/bcm/clk-iproc-pll.c
index 43a58ae5a89d..274441e2ddb2 100644
--- a/drivers/clk/bcm/clk-iproc-pll.c
+++ b/drivers/clk/bcm/clk-iproc-pll.c
@@ -744,8 +744,7 @@ void iproc_pll_clk_setup(struct device_node *node,
 	if (WARN_ON(!pll))
 		return;
 
-	clk_data = kzalloc(sizeof(*clk_data->hws) * num_clks +
-				sizeof(*clk_data), GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, num_clks), GFP_KERNEL);
 	if (WARN_ON(!clk_data))
 		goto err_clk_data;
 	clk_data->num = num_clks;
diff --git a/drivers/clk/berlin/bg2.c b/drivers/clk/berlin/bg2.c
index e7331ace0337..45fb888bf0a0 100644
--- a/drivers/clk/berlin/bg2.c
+++ b/drivers/clk/berlin/bg2.c
@@ -509,8 +509,7 @@ static void __init berlin2_clock_setup(struct device_node *np)
 	u8 avpll_flags = 0;
 	int n, ret;
 
-	clk_data = kzalloc(sizeof(*clk_data) +
-			   sizeof(*clk_data->hws) * MAX_CLKS, GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, MAX_CLKS), GFP_KERNEL);
 	if (!clk_data)
 		return;
 	clk_data->num = MAX_CLKS;
diff --git a/drivers/clk/berlin/bg2q.c b/drivers/clk/berlin/bg2q.c
index 67c270b143f7..db7364e15c8b 100644
--- a/drivers/clk/berlin/bg2q.c
+++ b/drivers/clk/berlin/bg2q.c
@@ -295,8 +295,7 @@ static void __init berlin2q_clock_setup(struct device_node *np)
 	struct clk_hw **hws;
 	int n, ret;
 
-	clk_data = kzalloc(sizeof(*clk_data) +
-			   sizeof(*clk_data->hws) * MAX_CLKS, GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, MAX_CLKS), GFP_KERNEL);
 	if (!clk_data)
 		return;
 	clk_data->num = MAX_CLKS;
diff --git a/drivers/clk/clk-asm9260.c b/drivers/clk/clk-asm9260.c
index bf0582cbbf38..44b544157121 100644
--- a/drivers/clk/clk-asm9260.c
+++ b/drivers/clk/clk-asm9260.c
@@ -273,8 +273,7 @@ static void __init asm9260_acc_init(struct device_node *np)
 	int n;
 	u32 accuracy = 0;
 
-	clk_data = kzalloc(sizeof(*clk_data) +
-			   sizeof(*clk_data->hws) * MAX_CLKS, GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, MAX_CLKS), GFP_KERNEL);
 	if (!clk_data)
 		return;
 	clk_data->num = MAX_CLKS;
diff --git a/drivers/clk/clk-aspeed.c b/drivers/clk/clk-aspeed.c
index 5eb50c31e455..7abe4232d282 100644
--- a/drivers/clk/clk-aspeed.c
+++ b/drivers/clk/clk-aspeed.c
@@ -627,9 +627,9 @@ static void __init aspeed_cc_init(struct device_node *np)
 	if (!scu_base)
 		return;
 
-	aspeed_clk_data = kzalloc(sizeof(*aspeed_clk_data) +
-			sizeof(*aspeed_clk_data->hws) * ASPEED_NUM_CLKS,
-			GFP_KERNEL);
+	aspeed_clk_data = kzalloc(struct_size(aspeed_clk_data, hws,
+					      ASPEED_NUM_CLKS),
+				  GFP_KERNEL);
 	if (!aspeed_clk_data)
 		return;
 
diff --git a/drivers/clk/clk-clps711x.c b/drivers/clk/clk-clps711x.c
index 9193f64561f6..2c04396402ab 100644
--- a/drivers/clk/clk-clps711x.c
+++ b/drivers/clk/clk-clps711x.c
@@ -54,9 +54,9 @@ static struct clps711x_clk * __init _clps711x_clk_init(void __iomem *base,
 	if (!base)
 		return ERR_PTR(-ENOMEM);
 
-	clps711x_clk = kzalloc(sizeof(*clps711x_clk) +
-			sizeof(*clps711x_clk->clk_data.hws) * CLPS711X_CLK_MAX,
-			GFP_KERNEL);
+	clps711x_clk = kzalloc(struct_size(clps711x_clk, clk_data.hws,
+					   CLPS711X_CLK_MAX),
+			       GFP_KERNEL);
 	if (!clps711x_clk)
 		return ERR_PTR(-ENOMEM);
 
diff --git a/drivers/clk/clk-efm32gg.c b/drivers/clk/clk-efm32gg.c
index f674778fb3ac..f37cf08ff7aa 100644
--- a/drivers/clk/clk-efm32gg.c
+++ b/drivers/clk/clk-efm32gg.c
@@ -25,8 +25,8 @@ static void __init efm32gg_cmu_init(struct device_node *np)
 	void __iomem *base;
 	struct clk_hw **hws;
 
-	clk_data = kzalloc(sizeof(*clk_data) +
-			   sizeof(*clk_data->hws) * CMU_MAX_CLKS, GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, CMU_MAX_CLKS),
+			   GFP_KERNEL);
 
 	if (!clk_data)
 		return;
diff --git a/drivers/clk/clk-gemini.c b/drivers/clk/clk-gemini.c
index 5e66e6c0205e..b51069e794ff 100644
--- a/drivers/clk/clk-gemini.c
+++ b/drivers/clk/clk-gemini.c
@@ -399,9 +399,9 @@ static void __init gemini_cc_init(struct device_node *np)
 	int ret;
 	int i;
 
-	gemini_clk_data = kzalloc(sizeof(*gemini_clk_data) +
-			sizeof(*gemini_clk_data->hws) * GEMINI_NUM_CLKS,
-			GFP_KERNEL);
+	gemini_clk_data = kzalloc(struct_size(gemini_clk_data, hws,
+					      GEMINI_NUM_CLKS),
+				  GFP_KERNEL);
 	if (!gemini_clk_data)
 		return;
 
diff --git a/drivers/clk/clk-stm32h7.c b/drivers/clk/clk-stm32h7.c
index db2b162c0d4c..d3271eca3779 100644
--- a/drivers/clk/clk-stm32h7.c
+++ b/drivers/clk/clk-stm32h7.c
@@ -1201,9 +1201,8 @@ static void __init stm32h7_rcc_init(struct device_node *np)
 	const char *hse_clk, *lse_clk, *i2s_clk;
 	struct regmap *pdrm;
 
-	clk_data = kzalloc(sizeof(*clk_data) +
-			sizeof(*clk_data->hws) * STM32H7_MAX_CLKS,
-			GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, STM32H7_MAX_CLKS),
+			   GFP_KERNEL);
 	if (!clk_data)
 		return;
 
diff --git a/drivers/clk/clk-stm32mp1.c b/drivers/clk/clk-stm32mp1.c
index edd3cf451401..83e8cd81674f 100644
--- a/drivers/clk/clk-stm32mp1.c
+++ b/drivers/clk/clk-stm32mp1.c
@@ -2060,9 +2060,8 @@ static int stm32_rcc_init(struct device_node *np,
 
 	max_binding =  data->maxbinding;
 
-	clk_data = kzalloc(sizeof(*clk_data) +
-				  sizeof(*clk_data->hws) * max_binding,
-				  GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, max_binding),
+			   GFP_KERNEL);
 	if (!clk_data)
 		return -ENOMEM;
 
diff --git a/drivers/clk/samsung/clk-exynos-clkout.c b/drivers/clk/samsung/clk-exynos-clkout.c
index f29fb5824005..9c95390d2d77 100644
--- a/drivers/clk/samsung/clk-exynos-clkout.c
+++ b/drivers/clk/samsung/clk-exynos-clkout.c
@@ -61,8 +61,7 @@ static void __init exynos_clkout_init(struct device_node *node, u32 mux_mask)
 	int ret;
 	int i;
 
-	clkout = kzalloc(sizeof(*clkout) +
-			 sizeof(*clkout->data.hws) * EXYNOS_CLKOUT_NR_CLKS,
+	clkout = kzalloc(struct_size(clkout, data.hws, EXYNOS_CLKOUT_NR_CLKS),
 			 GFP_KERNEL);
 	if (!clkout)
 		return;